Vapor detection of chemical warfare agents (CWA), toxic industrial compounds (TICs), solvents, fixed/permanent gases, explosives, greenhouse gases (GHG), water contaminants, etc. is commonly conducted with laboratory equipment and some portable equipment. Growing bacteria, including ordinary pathogens and biological warfare agents (BWA), also produce volatile organic chemical (VOC) signatures in vivo or in vitro that can be detected in the lab by high-performance vapor methods. High-performance VOC detection methods can also sense signatures of human odor, human gender, and identity.
One platform for VOC detection includes a pulsed discharge ionization detector (PDID). Generally, the PDID includes a plasma discharge source, an inlet for analytes from a gas chromatography (GC) column, and an array of electrodes. PDID can be operated in various modes, such as a pulsed discharge helium ionization detector (PDHID) mode, a pulsed discharge electron capture detector (PDECD) mode, and a pulsed discharge emission detector (PDED) mode. In the PDHID mode, the PDID employs a pulsed DC discharge in a gas to photoionize analytes eluting from the GC column, and electrons released from this photoionization process are directed to the electrode array. Changes in measured current provide the measurable detector response.
PDIDs provide enhanced sensitivity and selectivity when coupled with GC platforms. Implementing PDIDs in the field requires further development. For instance, miniaturization of PDID and GC instruments for field applications mandates reducing size, weight, and power requirements. Thus, new miniaturized PDID devices and systems are needed.